Solid phase of dense granular matter is inevitable because of jamming transition when the packing fraction or the pressure suffered is high enough. The experiment suggests that active Brownian granular matter will keep fluid phase even under the highest packing fraction (higher than the packing fraction of crystallization) if crystallization is prevented by mixing granular particles of different sizes. The findings encourage us to reconsider the role of activity in affecting the global dynamical properties of matter.
@article{arxiv.2604.14610,
title = {Absence of solid phase in dense amorphous active granular matter},
author = {Cunyuan Jiang},
journal= {arXiv preprint arXiv:2604.14610},
year = {2026}
}